Secret agent 543 is Ming Luo. Because Ming Luo sent a mysterious letter to the outside world, he was suspected to be a spy, but he arrived at the position in Shuoyang and asked Ming Luo to come and discuss the problem of repairing the guided car. Xiao Zhanwu lied that Ming Luo was ill. But this lie was soon exposed. Ming Luo knew that he was now regarded as a spy, and the whole people understood.

Top secret 543 plot

In the late 1950s, Chinese mainland's airspace was frequently invaded by the enemy, and the central government decided to set up an air force surface-to-air missile unit. A group of outstanding officers and men from all directions were ordered to be transferred to this mysterious unit code-named 543. Battalion Commander Xiao Zhanwu led a group of good soldier with their own characteristics to form the second team of Hero Camp, and made meritorious military service in the future. The whole battalion carried forward the fighting spirit of "one gun for the whole battalion", withstood the pressure of failed shooting and shot down the enemy reconnaissance plane in one fell swoop.

The record of shooting down a high-altitude reconnaissance plane with a surface-to-air missile is the first time in the history of world air defense. At the most difficult moment of building the army, the enemy resumed reconnaissance of the mainland. Faced with professional and technical problems, uneven casualties, shortage of missile spare parts and other unfavorable factors, the Second Battalion resolutely assumed the heavy responsibility of missile ambush and began an arduous field battle. In the end, the whole battalion overcame many difficulties and shot down many enemy U-2 high-altitude reconnaissance planes in one fell swoop, creating an unprecedented brilliant record.